What is electricity?

Let's talk about the electricity in a battery, and what's going on there.
See, there are two very reactive materials in a battery, one wanting to give up electrons and the other wanting to gain electrons. Unfortunately for them they aren't touching inside the battery so they can't just react that easily. Instead what they have to do is touch the same piece of metal.
From there, the side that wants electrons takes them from the metal while the other end is continually giving them to the metal.
This is the flow of charges that we call a current and this movement of electrons can be used to do work for us similar to how we can use water to spin a water wheel.